BEIJING (AP) - China's government has barred its two biggest oil producers from expanding their refining after they failed to meet pollution targets.

BEIJING (AP) China's government has barred its two biggest oil producers from expanding their refining after they failed to meet pollution targets.

The penalties for PetroChina and Sinopec are a fresh blow to China's state-owned oil industry following this week's announcement that four senior executives are under investigation for unspecified offenses.

The Ministry of the Environment said PetroChina and Sinopec failed to meet standards for reducing "chemical oxygen demand," a measure of pollutants released into bodies of water.

The ministry said because of that, the companies are barred from expanding or renovating oil refining capacity.

PetroChina Ltd. is Asia's biggest oil producer by volume and Sinopec, also called China Petroleum & Chemical Corp., is the region's biggest refiner.